diff --git a/include/boost/hana/ext/boost/tuple.hpp b/include/boost/hana/ext/boost/tuple.hpp
index 47e5fab3c..32c5c6658 100644
--- a/include/boost/hana/ext/boost/tuple.hpp
+++ b/include/boost/hana/ext/boost/tuple.hpp
@@ -12,6 +12,7 @@ Distributed under the Boost Software License, Version 1.0.
 
 #include <boost/hana/bool.hpp>
 #include <boost/hana/core.hpp>
+#include <boost/hana/iterable/foldable_instance.hpp>
 #include <boost/hana/iterable/mcd.hpp>
 #include <boost/hana/list/mcd.hpp>
 
diff --git a/include/boost/hana/ext/std/array.hpp b/include/boost/hana/ext/std/array.hpp
index f2c797c28..301912480 100644
--- a/include/boost/hana/ext/std/array.hpp
+++ b/include/boost/hana/ext/std/array.hpp
@@ -13,6 +13,7 @@ Distributed under the Boost Software License, Version 1.0.
 #include <boost/hana/bool.hpp>
 #include <boost/hana/core.hpp>
 #include <boost/hana/integral.hpp>
+#include <boost/hana/iterable/foldable_instance.hpp>
 #include <boost/hana/iterable/mcd.hpp>
 #include <boost/hana/list/mcd.hpp>
 #include <boost/hana/range.hpp>
diff --git a/include/boost/hana/ext/std/integer_sequence.hpp b/include/boost/hana/ext/std/integer_sequence.hpp
index 8167f3948..4eb47c45b 100644
--- a/include/boost/hana/ext/std/integer_sequence.hpp
+++ b/include/boost/hana/ext/std/integer_sequence.hpp
@@ -14,6 +14,7 @@ Distributed under the Boost Software License, Version 1.0.
 #include <boost/hana/comparable/equal_mcd.hpp>
 #include <boost/hana/core.hpp>
 #include <boost/hana/ext/std/integral_constant.hpp>
+#include <boost/hana/iterable/foldable_instance.hpp>
 #include <boost/hana/iterable/mcd.hpp>
 
 #include <type_traits>
diff --git a/include/boost/hana/ext/std/list.hpp b/include/boost/hana/ext/std/list.hpp
index 88efe336a..4f6f9fbb0 100644
--- a/include/boost/hana/ext/std/list.hpp
+++ b/include/boost/hana/ext/std/list.hpp
@@ -12,6 +12,7 @@ Distributed under the Boost Software License, Version 1.0.
 
 #include <boost/hana/core.hpp>
 #include <boost/hana/functor/fmap_mcd.hpp>
+#include <boost/hana/iterable/foldable_instance.hpp>
 #include <boost/hana/iterable/mcd.hpp>
 
 #include <list>
diff --git a/include/boost/hana/ext/std/tuple.hpp b/include/boost/hana/ext/std/tuple.hpp
index 0da691707..ea7ed7dfd 100644
--- a/include/boost/hana/ext/std/tuple.hpp
+++ b/include/boost/hana/ext/std/tuple.hpp
@@ -14,6 +14,7 @@ Distributed under the Boost Software License, Version 1.0.
 #include <boost/hana/bool.hpp>
 #include <boost/hana/core.hpp>
 #include <boost/hana/functor/fmap_mcd.hpp>
+#include <boost/hana/iterable/foldable_instance.hpp>
 #include <boost/hana/iterable/mcd.hpp>
 #include <boost/hana/list/mcd.hpp>
 #include <boost/hana/monad/flatten_mcd.hpp>
diff --git a/test/sandbox/repeat.cpp b/test/sandbox/repeat.cpp
index 16fc0b458..7fcba6450 100644
--- a/test/sandbox/repeat.cpp
+++ b/test/sandbox/repeat.cpp
@@ -8,6 +8,7 @@ Distributed under the Boost Software License, Version 1.0.
 #include <boost/hana/detail/static_assert.hpp>
 #include <boost/hana/functional.hpp>
 #include <boost/hana/integral.hpp>
+#include <boost/hana/iterable/foldable_instance.hpp>
 #include <boost/hana/iterable/mcd.hpp>
 #include <boost/hana/lazy.hpp>
 #include <boost/hana/list/instance.hpp>